Flanging machine



July 10, 1923.

H. M CABE FLANGING MACHINE Filed July 51 1922 limzwa a/ rz. I

M g a M/ a. 6 WW/ 4 w 7 Patented July 10, 1923.

, UNITED srarss 1,451,041 PATENT caries.-

HUGH M'GGABIE, or LAWR NCE, MASSACHUSETTS.

FLANGING MACHINE.

Application filed July 31, 1922. seriai'ivo. 578,589.

, provement infianging machines.

In the Hanging Fmach'ne "of the McCab Patent No. '1,006,861,, the clamp plate 3 is pressed up by the wedge 5, to clampthe work against the top clamp plate 6 to hold the work during "the Hanging operation. This clamp plate 3, it will be seen by reference to such patent, was supported to resist the pres sureof the bender by a shoulder on the front ofthe machine against which it took. WVith each thickness ofmetal plate to be operated upon-by this machine, there is provideda clamp plate corresponding to the clamp plate 3 of such a length that its edge opposed to the bender is at the proper distance therefrom when. the bender is in lowermost position. Experience with machines of this type has shown that operatives sometimes neglect to put in the proper plate suitable for the thickness of the sheet metal being operated upon. Thus. for example, if a plate 3, suitable for use with one-quarter inch plate, was in the machine, and an operative were to put in a piece of half-inch plate and operate the machine, it is obvious that an enormous pressure will be exerted upon the edge of the plate 3, tending to force it away from the bender. This strain has been found to be so great that the frames of the machine have been repeatedly broken. The remedy which seemed to be necessary to be applied was to increase the strength of the frame, but obviously there are limits to which it is desirable to increase the strength of the frame because in flanging very heavy sheet metal such as three-quarter inch boiler plate to double thickness of the plate, or some other such extent, might even break such a machine, as the power applied to the bender by the pneumatic piston which actuates it is very great.

The object of the present invention is to provide the machine with a breaker piece adapted normally to support the plate 3 against the working pressures incident to Hanging metal, but which, when such plate is subjected to the enormous stresses due to the introduction of a piece of boiler plate of greater thickness than that for whichthe machine is arranged, will break, requiring no more than a trifling replacement of the broken piece in order to put the machine in condition for further use, To this end the invention consists in the improvement hereinafter described and in the claims.

In the accompanyingdrawing illustrating the preferred form of the invention, Figure particularly defined 1 1s a fragmentary side elevation of a portion of a McCabe flanging machine, showing the main operative parts; and Fig. 2 is a plan of the frame and bottom clamp plate, showing the breaker pieces in position.

The illustrated embodiment of the inven tion is described as follows: The top. clamp 1, the frame Q, and the bender 3, are or may be all constructed as in such patented machine, except as". hereinafter mentioned. The front end 4 of the frame is provided with the segment groove 5, which is adapted to receive the T-head slide of the segment 6 which carries the bender 3. The. bottom clamp plate 7 provided with atongue 8. which extends into the narrow portion of the segment slot 5. It is provided with a recess 9, which receives the pin 10 by which it is prevented from accidental displacement from the machine. The wedge block 11 operates in the manner of said patent, to raise and press the clamp plate 7 against the sheet of metal 12 introduced into the machine. At the front end of the bottom clamp plate 7 there are provided two plate supporting hardened steel wedge pieces 13, against which the front edge of the bottom clamp plate 7 engages. These wedge pieces 13 are machined to fit correspondingly machined recesses in the frame piece 4, and are normally held in place by the screws 14. The angle of the wedge pieces 13 is such that for all ordinary pressures which the machine is intended to stand, the coefficient of friction between the wedge pieces and the frame will be such as to prevent the sliding of the wedge pieces in their recesses on the frame by means of the comparatively light and frail screws 14. Thus, with a piece of metal to be flanged, such as is shown in Fig. 1, and with the edge of the bottom clamp plate occupying the position shown with relation to the bender, the pressure exerted by the bender'upon the bottom clamp plate will be such as may be carried with safety by the wedge pieces and the screws. If, now, the operative were to insert a piece of boiler plate in the machine, say an eighth of an inch thicker than that for which it was adjusted, and should attempt to form a flange thereon by operating the machine, it will be obvious that when the parts attempted to assume the position shown in Fig. 1, an enormous longitudinal pressure would be exerted upon the bottom clamp plate 7, tending to slide it forward. This enormous pressure would be sufficient to squeeze out the wedge pieces 13, shearing off the screws 14 without injury to the machine. By the simple removal of the screws and their replacement with new ones, the machine would again be ready for work. The expense of replacing an entire frame, which is a casting of great weight ordinarily made of cast steel and requiring expensive machining would be saved.

I am aware that breaker pieces have been introducedin machinery to save expensive parts from injury owing to the introduction of excessive strains due to some inadvertence, butso far as I am informed. I am the first to avail myself of the use of a wedge shaped piece in a wedge-shaped recess which, by the coefficient of friction between the parts, will oppose all ordinary stresses to which it is subjected without movement, but which, under excessive pressures, will be permitted to slideand shear off or break such slight holding means as may be required in addition for securing the wedgeshaped pieces from movement.

Viewed in its broader aspects, the invention contemplates the employment of a wedge-shaped piece in a correspondingly shaped recess, lightly held in position by some device adapted to be broken under excessive strain. The invention consists in opposing the working strains by the coeflicient of friction between inclined faces li htly held in proper position,

Having thus describedthe invention, what is claimed is:

1. A breaker piece for a machine having a flat face to receive the working pressure of a part thereon, and an opposed inclined face supported by another part of the machine correspondingly inclined, theangle of inclination of the faces being such that the coeflicient of friction-between the inclined faces will be substantially ample to resist a the working strains of the machine, and slight means for holding the inclined piece in position.

2. A flanging machine having, in combination, a clamp provided with a movable clamping member, and a stationary clamping member for clamping and holding the work to be operated upon, a bender, and means for moving it around the corner of the clamping plate to form a flange on the metal, a wedge piece having a straight face engaging the clamp plate, and. an inclined face, a portion of the frame of the machine being provided with a correspondingly inclined face to receive and normally support the wedge piece, and light means for holding the wedge piece in position adapted to be broken under excessive pressures.

HUGH MQCABE. 

